What does the 106.9 coverage pattern look liike? It could very well be inferior to 570's coverage to the east and west, but IIRC WSYR has a real problem with its AM coverage to the south of town, including the southern half of Onondaga County--especially on the nighttime/pre-sunrise pattern. They could be picking up some added listeners in the burbs on FM.
Having said that, they're messing up the whole cluster, and wasting an urban format on 620. The 620 facility is actually better both day and night in hitting the adult core audience in the market than 570, and maybe even better than 106.9, so its real natural format is news/talk. They'd have been best off moving the sports to 570 (which is still a better pattern than 1260, especially after dark), moving news/talk to 620, and keeping the urban contemp at 106.9. That format on FM, if well done, has excellent potential for dominating 12-34 listenership in both city and suburb and cutting across ethnic and income lines, while a superior-coverage signal on 620 would get the 35+ crowd with news and talk. Just ask the Langston family in Rochester, who have taken such a station, WDKX (FM), straight to the top 12+ in Rochester despite one of the weakest FM signals in the Rochester market.